Examples of non-voice services provided through a mobile communication network include a “non-voice service over NAS” that receives a service provided from a server using a control signal through a 2G (GERAN)/3G (UTRAN) core network, and a “non-voice service over IP” that receives a service provided from a server through an IMS on an IP basis. FIG. 11 illustrates a schematic configuration diagram of a network that provides non-voice services. Message services among the non-voice services particularly include unstructured supplementary service data (USSD) mainly provided by a GSM (registered trademark), a short message service (SMS) specified in the 3rd generation partnership project (3GPP), and the like.
The message service with the USSD and the short message service (SMS) are used as text communications between terminals (mobile stations and the like). In addition, the USSD is used in an application program for performing text chat, and is also used for an additional service setting control on a text basis. The USSD is broadly divided into two types of a “USSD over IP” and a “USSD over NAS”. FIG. 12 illustrates a schematic configuration example of such USSDs.
The SMS provided by the 3GPP is broadly divided into two types of an “SMS over IP” and an “SMS over NAS”. FIG. 1 illustrates a schematic configuration example of such SMSs.
As illustrated in FIG. 1, the “SMS over NAS” is available in the 2G (GERAN)/3G (UTRAN) and an LTE (E-UTRAN), and includes three types of an SMS over SGs, an SMS over CS, and an SMS over PS. Moreover, the “SMS over IP” is available only in the LTE (E-UTRAN).
Moreover, the 3GPP specifies that whether the SMS over IP is used with higher priority, or the SMS over IP is not used, in other words, the SMS over NAS is used can be set for a mobile station in advance (for example, NON-PATENT DOCUMENT 1).